It has always been desirable to compare one acceptable surface of one article, (or a collection of acceptable surfaces of a collection of articles), with a second surface of a second article so as to detect and correct the cause of any undesirable surface deformities that may exist in the second surface.
For example, in the case of the outer surface of an automobile, any visible surface deformities, such as waviness in the surface, or "orange peel" in the paint surface, that can be eliminated enhance the esthetic and therefore the commercial value of the entire automobile. The competitive need to eliminate undesirable surface deformities in an automobile's outer surface becomes particularly important in the case of exterior automobile panels fabricated from fiber reinforced plastics, i.e., fiberglass components, wherein the panel may already have a certain degree of waviness due to the fiberglass mold conditions, resin cure rates, or other conditions of the fabrication process that tend to generate a surface waviness.
One surface deformity measurement system has been developed by the Budd Company, Plastic Research and Development Center, Troy, Mich. The Budd system moves a height gauge across the surface to be studied in order to attempt to measure the minute dimensions of surface deformities. This system is highly susceptible to background vibrations, can only measure one linear foot at a time, and is impractically slow in analyzing a large area. The system, due to these and other mechanical limitations, has not been placed in extensive use.
Another Diffracto Sight system, offered for sale by Diffracto, Inc., P. O. Box 36716, Grosse Point Woods, Detroit, Mich. 48236, is also available wherein light is reflected off the surface of interest, the light then being viewed through special lens worn by the viewer. The system merely yields a visual representation of any surface deformities, with no means of reducing the viewed image of the distorted surface into any type of objective format for further study.
A system need be developed, therefore, that presents any undesirable deformities in a surface in a readily visible format, the system also being capable of reducing the observed deformities into an objective format for further analysis. Such a system should identify the location of any unacceptable surface deformities, and also perform an objective and quantitative analysis as to the extent and magnitude of these deformities.